Non-linking Documents And Images: Local Or Remote?

One of my clients has a limited amount of hosting space, so to save space I thought of putting their images on Flickr and their PDF documents on Google Docs. If I'm linking off-site to them in this way, is that likely to hurt the rankings of my regular pages or the site overall? I realize that adding pages of content normally boosts the whole site because of internal linking, a "rising tide lifting all boats" effect; but for documents and images that don't link back to the rest of the site, can they have that effect? Thanks.

(They would lose the little bit of direct traffic they get from Google Images, but I doubt much of that is well targeted, and if those people find themselves at Flickr, there will still be a link to the site from there if they're looking for more than the image. They'd also have the opportunity of picking up new 'social media driven' traffic from searches at Flickr, I suppose.)